Microbial fuel cells work by converting chemical
energy in the chemical bonds of organic compound
to electrical energy through catalytic reactions
of micro-organisms under anaerobic conditions.
In the chamber, the anode short-circuits the
natural electrons acceptors. The protons then
pass through the proton-selective membrane
towards the aerobic chamber. The electrons
produced are transferred to the cathode, here
they reduce oxygen to form water. Electrons
transfer from the microbial cell to the anode
occurs either via membrane-associated components
or via soluble electron shuttles termed
mediators. Figure 1 shows a scheme of a
microbial fuel cell.

For my experiment, I would be covering two
parts:

I will be
investigating how different concentrations of
organic matter in lake water obtained from Leazes Park will affect current density output.
Concentration of organic matter would be changed
by addition of glucose to the lake water.

I will be verifying the hypothesis that
concentration of organic matter in a microbial
fuel cell is linearly proportional to its
current output. For this experiment, lactate is
used as the organic matter and its concentration
is varied.

Current challenges faced are the long time
required to obtain a measurement (more than
24hrs). During my project, I will be looking
into improving the efficiency of the microbial
fuel cell system by the addition of substrate
chitin to test if the hypothesis holds true.